nashdm2

BMW 520d B47 Engine Fuel Consumption

193 posts in this topic

Guys, I have decided to start a thread dedicated to this subject as it has been discussed on a couple of other threads, but not under the correct title.

 

It needs discussing more as I do believe we have an issue with this engine. I have had many diesel BMW's and have always got very close to the promised MPG. On my F11 with the B47 engine in, I have got nowhere near it after 8k miles.

 

My dealer has stated that he regularly drives the same route to work every day. He has had a N47 1 series and after 4 months into it, he swapped to the B47 1 series. Over exactly the same route and conditions, his B47 journeys are regularly 10 mpg worse.

 

So, why is this? We know about the Euro 6 standards, and the regen process that is always "heard" in the B47. I did see a post where somebody had cut and pasted a chart detailing the Euro standards and potentially would explain why, but in that case, you would expect to see BMW publish lower expected MPG figures, which we know is not the case.

 

My total MPG for the 8k miles is 43. I do not think my particular car has a "fault" as such, as others are having the same. This engine has been around now for some 18 months and I am quite shocked this story is not all over the web.

 

It would be good to discuss this at length on this thread please.

 

Please can I ask that N47, 530d, 535d owners do not put their mpg performances up as they will be in most case, the same or better than the B47, so, although interesting, not constructive (sorry, did not mean to offend)

 

Thanks in advance guys.....................let the discussion begin.

 

 

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Some data to show the issue, from Spritmonitor. These graphs are for N47 and B47 F10 and F11 520d's.

 

N47:

 

chrome_2016-03-11_08-51-06.png.c595f20e6

 

B47:

 

chrome_2016-03-11_08-46-49.png.9f09df91e

 

The average is a drop of 3.5, but there is a small sample on the B47 (24 cars compared to 183 cars for the N47) and you could argue that the top of the normal distribution is very similar for both engines (41.1 vs 41.8).

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Hey Pottsy, thanks for the great contribution, a very interesting read for sure. I know you have pointed out the small sample size for the B47, but, I was expecting a greater difference from the two engines.

 

Where does it come from please and is this representative of a particular country?

 

Thanks, Dave

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8k miles is still pretty new and tight I would give it double that mileage and I'm sure you will see a fuel increase especially after its had it's first service.

Don't forget its a LARGE HEAVY car and 43 average for this time of year is good IMHO , my wife has a small 1 litre eco boost fiesta and that is averaging 39mpg official figures says 58.

 

Forget what the official figures state as they are done under laboratory conditions not real life. Again 43 is not that bad and average I would say for that engine in that car.

 

Turn Off your MPG display and enjoy the car ;)

Edited by n0chex
sshooie likes this

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Hi n0chex, thanks.

 

Don't get me wrong, in every other way I can think of, I love the car, it is amazing. My 43 mpg was across the last 14 months, so, a spread of weather conditions. Also, your point that 8k is still low is correct.

 

I think what I am really trying to get at is not necessarily that my fuel consumption is dreadful for the type of car, its more about what BMW have promised and also the comparison against the previous versions of the engine. All the other BMW variants are having issues with the B47 fuel consumption. If BMW in their brochure had said, that in order to hit the Euro 6 emissions standards, you are going to have to accept that the fuel consumption in your car is going to be worse that the previous N47 variant, I would not have an issue. But, they are not saying that. The brochure quotes figures that are better than the previous model, but most owners are seeing something different.

 

Once again, I am, sure that my car does not have a "fault" over other B47 equipped F10/11's. So why is it and what is going on is my real question.

 

I love the car, it is the best car I have ever owned, period. I love driving it. Just a tad curious as to what is going on.

 

Hope that helps, Dave

  

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My average mpg is pretty much as above and, although I have seen the mpg display indicating well over 50 mpg, it never lasts because it takes a lot of fuel to get 2 tonnes of metal moving. I've found that keep the car rolling on a level motorway at speeds below 65 mph and I can see phenomenal mpg but venture above 65 and add hills and traffic to the mix and mpg drops like a stone. I came from an e90 (N47) which averaged high 40s and, having swallowed the BMW mpg hype for the B47, I didn't expect to see too much of a drop, so I have to admit to being surprised and disappointed that low 40s in the norm for my F10 (B47) after 17000 miles. I should add that these figures are indicated, I don't bother working it out as it might upset me :rolleyes:

 

I should add that I must be losing at least 2 to 3 mpg thanks to the proliferation of mini roundabouts, speed humps and concrete chicanes etc, which does seem counter productive as far as government emission levels are concerned.

 

Like nashdm2, I love the car and I don't worry too much about the mpg as it's such a joy to drive (apart from the throttle response (lag) in Comfort mode :( ) but I'll be very interested to see if anyone is getting better fuel consumption without driving Miss Daisy.

 

 

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Interesting topic and wish I read if sooner. I have my LCI F10 arriving on Friday (B47 520d) and I've come from a N47 520d) which I had great consumption in, I'd say low 50s are common and even got 910miles from a full tank. I saw the mpg figures of the new one and instantly thought awesome I'll get better Mpg but I see the b47 is far worse. It's more powerful at 190bhp, is that why actual mpg lower? What's the regen noise about? Have I bought a guzzler when I loved my N47 for the economy? What's the b47 535d like in comparison with the b47 520d? Is the gap closer than it was?

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Regen sounds like there's a hole in the exhaust, it's not that loud, just a deeper and more noticeable note for about 10 minutes. When I first heard it I thought wtf has gone wrong,  :wub:  then the penny dropped  :D

 

I wouldn't exactly day the B47 is a guzzler, but there again, neither does it live up to official mpg figures.

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I have a B47 520d, and have covered  9,000 miles in 10 months.  My average fuel consumption is 40 mpg. Majority of my journeys are my commute to work which is 12 miles each may, max speed 50 mph.

 

took it back to Dck Lovett in Bristol and got them to look at why this is so poor (literature says expect 53 to 57 mpg Urban, average 61), very disappointing as I am a really careful driver, use ECO Pro mode all the time, rarely exceed speed limits, use cruise control and the coasting mode where I can.  They said they couldn't find anything causing the issue.

 

I've had the car from new and love it - apart from this.  Bahhh!!

image.jpg

image.jpg

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You will never reach consumption from folder. Secondly diesel efficiency starts when engine is fully warmed up. This can be achieved only after 7-10 miles depends of the outside temperature. So I think 40 mpg in this circumstances is pretty good. I would rather consider petrol when driving that short distance.

Sent from my D6503 using Tapatalk

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Or a Toyota Prius :)......On a sensible note you have a 2 litre performance diesel 190BHP and 40 mpg plus Urban I would say is good for the size and weight of the car.

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3 hours ago, IanS100 said:

cruise control and the coasting mode

 

What is the "coasting mode"

 Extract from the manual:

Coasting

Principle

The system helps to save fuel.
To do this, the engine is automatically disconnected from the gearbox in selector lever position D under certain circumstances. The vehicle continues to roll in idle to reduce consumption. Selector lever position D remains engaged.
This vehicle condition is called coasting.
As soon as the brake or accelerator pedal is depressed, the engine is automatically connected again.
 
 
I think that this was from B47 Engine and new automatic gearbox (7/2014)
 
It only works in Eco Pro (and if selected in iDrive) and does not work with cruise control.
 

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My 12000 mile 2015 F10 520d seems to be ok for mpg. Averaging 49.5mpg on 75% M25 and 25% shorter runs. Got 63.4mpg on a quietish 40 mile journey last week according to trip computer with average speed of 53.9 mph.

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10 hours ago, Dave777 said:

My 12000 mile 2015 F10 520d seems to be ok for mpg. Averaging 49.5mpg on 75% M25 and 25% shorter runs. Got 63.4mpg on a quietish 40 mile journey last week according to trip computer with average speed of 53.9 mph.

 

I guess that is a product of the type of miles and driving you are doing. Thanks  

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Carrman: I thought you meant it was a selectable mode. From what I'd read I didn't think it applied to 2.0d engine, I've used eco pro a few times but never thought that coasting was any different to comfort mode, I'll have to have another go.

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3 hours ago, IanS100 said:

Carrman: I thought you meant it was a selectable mode. From what I'd read I didn't think it applied to 2.0d engine, I've used eco pro a few times but never thought that coasting was any different to comfort mode, I'll have to have another go.

It is selectable in as far as you have to tick a box under Eco Pro Settings in the iDrive.

 

It does feel distinctly different in that it tends to run away with itself and you also notice when drive reengages.

 

It is clear when it is coasting from my Multi Function Display as follows:

 

Display in the instrument display

25133002.jpg
 
 
 
 
 
 
The marking in the efficiency display has a blue background and is at zero.
The coasting point display is illuminated at zero when coasting.
 
I don't know what it shows if you only have the standard Black Panel Display.
 

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Guys, just to bring this back to the top and also see if anybody has any recent updates or experiences please?

 

Dave

Edited by nashdm2

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Doing 40.1 mpg driving like a granny. Two tankfuls with two longer journeys of 100 miles apiece. Most of my journies are on country roads with rolling hills over about 10 miles. Little town work.

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My one week old 520d (2016) is absolutely appalling!!! From coming from a 2013 N47 engine which was amazing, I am a bit wounded. The dealer filled up a full tank and I only got 300miles from it!!! Yes I didn't do any long motorway runs, all local but the same in my old car would've got me close to 450-500. 850 on a long run. The average MPG was showing as 22mpg and I don't have a heavy right foot. I'm hoping the next few tanks give me better. 

 

When i I got my n47, I immediately got amazing consumption from the delivery miles but this time I haven't. I did have some burning smell with the b47 but it has subsided and the exhaust note is awful, like an exhaust that is blowing or leaking (husky tone, like a drone sound)

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My 520d is approaching 1 month old and now shows average mpg of 42.3 - mainly short trips to be fair.  Seems to be improving - 600 mile trip over Easter averaged 50.6.  I don't think it will be as good as my old M47 520d, which managed 64.1mpg on a trip when it was just over a month old 10 years ago.  Lucky fuel prices are still low.

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12 hours ago, bobbywalrus said:

My one week old 520d (2016) is absolutely appalling!!! From coming from a 2013 N47 engine which was amazing, I am a bit wounded. The dealer filled up a full tank and I only got 300miles from it!!! Yes I didn't do any long motorway runs, all local but the same in my old car would've got me close to 450-500. 850 on a long run. The average MPG was showing as 22mpg and I don't have a heavy right foot. I'm hoping the next few tanks give me better. 

 

When i I got my n47, I immediately got amazing consumption from the delivery miles but this time I haven't. I did have some burning smell with the b47 but it has subsided and the exhaust note is awful, like an exhaust that is blowing or leaking (husky tone, like a drone sound)

 

Wow, that is seriously bad, a lot worse than some of the very bad reports on this thread.

 

I think you need to do you own complete fill up and see how it goes from there as perhaps the dealer did not do a complete fill as mine will sometimes show full for the first 90-100 miles.

 

 

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Nearly 12k miles in and 39.3 mpg average approx 80% town driving with cold engine. I am starting to see an improvement as the engine is bedding in.

Edited by McFar67

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